Combining ability analysis in sunflower (Helianthus annuus L.)

A study was carried out to assess the combining ability of ten CMS lines with four testers using the line x tester method. Biometrical observations were taken for days to 50% flowering, plant height, head diameter, days to maturity, volume weight, hundred seed weight, seed yield /plant, oil content and oil yield/plant. Specific combing ability variance was greater than the general combining ability variance for all the characters which indicated that non-additive gene action played a major role in inheritance. The gca of parents were not in agreement with the per se performance for various traits. Hence, the selection of parents should be based on gca alone for a breeding programme. Three lines viz., COSF 12A, COSF 13A and CMS 207A, and tester IR 6 were identified as good general combiners for seed and oil yield. Among the hybrids generated using good general combiners, COSF 13A x IR 6 had the additive type of gene action for seed and oil yield per plant. In general, most of the crosses had non-significant sca for oil yield per plant and oil content which indicated the presence of an additive type of gene action. Hence, the selection of good general combiners for oil content, seed and oil yield will help to evolve high oil yielding hybrids in sunflowers.